1. Field of the Invention
The present invention relates to an image forming apparatus such as: a copier, a printer, a facsimile apparatus, a multi-function apparatus, etc.; a unit for installation in the image forming apparatus in a replaceable manner; and an administration system monitoring the status of the image forming apparatus.
2. Discussion of the Background
In an image forming apparatus such as a color copier, a printer, etc., a number of units for installation in the image forming apparatus, such as a process cartridge, etc., are configured to be freely detachable from the main body of the apparatus. In such an image forming apparatus, when a unit in the apparatus is exhausted or malfunctions, the unit is replaced by the user or service person with another unit in mint condition.
Here, units in mint condition include a new unit manufactured at a factory and a recycled unit which has been collected after having been used in an image forming apparatus and processed for recycling at a recycling factory.
Recently, with rising of consciousness of resource saving, recycled units for image forming apparatuses are increasingly provided by manufacturers other than manufacturers of image forming apparatuses.
On the other hand, a technology to control an image forming apparatus according to information on a process cartridge installed in the main body of the image forming apparatus in a replaceable manner is disclosed, for example, in Japanese Patent laid-open publication No. 2001-296786. Specifically, when the type of an installed process cartridge has been determined to be one of the listed types, the image forming apparatus is controlled in conformity with the installed process cartridge. When the type of the installed process cartridge has been determined not to be one of the listed types, image formation is unconditionally prohibited.
Japanese Patent laid-open publication No. 2002-120438 describes a technology to obtain a main control program optimum for a process cartridge installed in the main body of an image forming apparatus in a replaceable manner, according to an ID of the process cartridge, via a network. Specifically, first, the version of the main control program corresponding to the ID of the process cartridge is checked, and then, the main control program corresponding to the version is downloaded to the image forming apparatus via the network.
In the above-described image forming apparatus, when a process cartridge has been replaced with a new one or a recycled one, sometimes the image quality of the output image deteriorates.
More specifically, when an image forming apparatus is manufactured at a factory, various adjustments are made to the image forming apparatus in the state that a process cartridge has been installed in the main body of the apparatus. The adjustments include fine adjustments to obtain the best image quality, and a considerable number of adjustments are made to the process cartridge and the main body of the apparatus in one-to-one correspondence. Therefore, if the process cartridge in the main body of the image forming apparatus after such adjustments have been made is replaced with another process cartridge, then often image quality that is exactly the same as the one obtained in the apparatus before the process cartridge has been replaced cannot be duplicated.
The above-described problem becomes obvious in an image forming apparatus used at a customer's place when a service person performs replacement in the image forming apparatus. That is, when a process cartridge installed in an image forming apparatus becomes exhausted or malfunctions and is replaced with a replacement process cartridge, image quality of the apparatus sometimes deteriorates.
When the replacement process cartridge is one of the manufacturer's parts (quality of which is overseen by the manufacturer of the image forming apparatus), difference in image quality before and after making replacement of the process cartridge with the replacement process cartridge is nearly unnoticeable. This is because the image forming apparatus, the process cartridge, and the replacement process cartridge are designed and manufactured such that even when replacement of the process cartridge with the replacement process cartridge is made in the image forming apparatus, the difference in image quality before and after making the replacement is minimal. The same applies to a recycled process cartridge recycled by the manufacturer of the image forming apparatus.
On the other hand, when the replacement process cartridge is one manufactured by a manufacturer other than the manufacturer of the image forming apparatus (the quality of which are not overseen by the manufacturer of the image forming apparatus), there is a possibility that the difference in image quality before and after replacement of a process cartridge with the replacement process cartridge is not negligible. This is because there is a possibility that the replacement process cartridge is not designed and manufactured such that when replacement of a process cartridge with the replacement process cartridge is made in an image forming apparatus, difference in image quality before and after the replacement is minimum. The same applies to a recycled process cartridge recycled by a manufacturer other than the manufacture of the image forming apparatus. Recycled process cartridges may include those process cartridges manufactured by the manufacturer of an image forming apparatus and recycled by a manufacturer other than the manufacturer of the image forming apparatus and those process cartridges manufactured and recycled by the manufacturer other than the manufacturer of the image forming apparatus.
The technology described in Japanese Patent laid-open publication No. 2002-120438 cannot optimize image quality in an image forming apparatus when such a process cartridge, the quality of which is not overseen by the manufacturer of the image forming apparatus, is installed in the apparatus as a replacement.
The above-described problem in image quality might not be negligible in particular in color image forming apparatuses in which relatively high image quality is demanded.
In relation to the above-described problem, for example, Japanese Patent laid-open publications No. 2003-29583 and No. 2003-58003 describe a technology to disable installment of a process cartridge that cannot be identified, in the main body of an image forming apparatus, e.g., a process cartridge manufactured by a manufacturer other than the manufacturer of the image forming apparatus.
However, among those process cartridges manufactured by a manufacturer other than the manufacturer of an image forming apparatus, there may be one that, when installed in the image forming apparatus as a replacement, can maintain satisfactory image quality comparable with the image quality obtained when a process cartridge manufactured by the manufacturer of the image forming apparatus is installed in the apparatus. In particular, even when a replacement recycled process cartridge is one of those processed for recycling by a manufacturer other than the manufacturer of an image forming apparatus, if the replacement recycled process cartridge is the one manufactured by the manufacturer of the image forming apparatus, there is a strong possibility that satisfactory image quality can be maintained. Forbidding installment of such a replacement recycled process cartridge in an image forming apparatus across the board restricts alternatives for the user of the image forming apparatus, which is inappropriate.
The above-described problem is common to each unit that is configured to be installed in the main body of an image forming apparatus in a replaceable manner and that, when installed in the main body of the image forming apparatus to replace a previously installed unit, may cause differences in image quality before and after installment of the unit in the main body of the image forming apparatus, e.g., a photoconductor drum, a charging unit, a development unit, a toner cartridge, a cleaning unit, an optical unit, a transfer unit, a sheet feeding unit, a fixing unit, etc.